Thermal insulation



Aug. 11, 1936. J. M LE GRAND THERMAL INSULATION Aug. v11, 1936. J. M.L l: GRAND THERMAL INSULATION l Filed'April l, 1953 8 Sheets-Sheet 5 :MN um ohhh wh MN @m NN uw, @N Nh @NSN NNNSNNS QN www mv,

QN. km.

b. QN km.

QQ Mw, MG.

NN NM KM Q@ Align, 1935 J. M. 1.12:4 GRAND THERMAL INSULATION Filed April l, 1935 8 Sheets-Sheet 4 y 'fos Aug. 11, 1936. 1,A M LE GRAND THERMAL INSULATION v Filed April l 8 Sheets-Sheet 5 A @QN/07 fOSePp/ M@ @Wa/M ug. 11, 1936. J. M. LE GRAND 2,050,663

THERMAL INSULAT ION Filed April l, 1933 .8 Sheets-Sheet 6 Aug. 11, 1936. J. M. LE GRAND THERMAL INSULATION Filed April 1 1953 8 Sheets-Sheet 7 @era/L07@ Allg- 11, 1936- J. M. I E GRAND 2,050,663

' THERMAL INSULATION n Filed -April l, 1933 8 ASheeS--Sheet 8 f J N L\ in N N w Q f @u N QN gi N N ,W y 51 m I i v N \Q u fm@ A Y A Wx m f N w Qn m QW N\ \Q\ M N 1 a Q L@ tg Y ,N gw f a w A M A 'k SH w a/@mien Patented Aug. 11, 1936 UNITED STATES PATENT OFFICE y 2,050,663 l 1 THERMAL INSULATION Joseph Le Grand, Chicago, Ill.

Application April 1, 1933, Serial No. 663,934

17 Claims.

structures of this character in which the walls thereof are insulated against the transmission of heat therethrough.

One of the objects is to provide an improved structure of the foregoing character which is simple in construction, is inexpensive to manufac- Iture, and insures increased thermal insulation efciency at lower cost.

Another object is to provide an improved structure of the foregoing character embodying the thermal insulation features disclosed in my copending application, Serial No. 629,089, (now Patent 1,910,703) of which this application is a continuation-impart,

A further object is to provide insulating means constructed and arranged to fonn disconnected, uni-planar spaces along the walls of the structure to be insulated, which spaces are sub-divided into a plurality of disconnected, substantially seated, ,uni-planar chambers substantially free fromv convection currents.

Another object is to provide an improved insulating means for walls and the like, which means includes a plurality of metallic sheets secured together in spaced relation by a rigid frame structure which serves to stiffen the walls and to support, brace and strengthen such walls; whereby the latter may be formed from relatively thin, light weight and inexpensive sheet material without sacrifice in strength, durability and efciency of the structure as a whole.

An additional object is to form an improved walled structure which is provided with thermallyinsulated walls not materially affected by psychrometric conditions and which are practically free from condensation and the elects thereof; which is thermally insulated in a substantially uniform manner throughout its several walls; which is substantially fire-proof; which is proof against vermin, insects, rodents, bacteria and various gases; which may be readily and quickly assembled and disassembled; and which insures maximum eiciency, substantially throughout the life of the structure, in insulating against the transfer of heat through the walls by radiation, conduction and convection.

Other objects and advantageswill become apparent as this description progresses and by reference to the drawings wherein my invention is illustrated in its application to household refrigerator cabinet embodying the invention and l taken substantially on line I-I of Fig. 2;

Fig. 2 is a vertical sectional view taken substanltially on line 2 2 of Fig. 1;

Fig. 3 is an enlarged horizontal section taken 5 substantially on line 3-3 of Fig. 1;

Fig. 4 is a separated, perspective view of the insulation unit which forms a part of the back Wall of the cabinet shown in Figs. l to 3, inclusive,

V the central portion and a part of the bottom edge of such unit being cut away to more clearly show the structureV of the same;

Fig. 5 is a view similar to Fig. 4 except showing one of the side wall insulating units of Fig. 3;

Fig. 6 is a view similar to Fig. 4 except showing 15 the door insulating unit of Fig. 3;

Fig. 7 is a view similar to Fig. 4 except showing the bottom wall unit of Fig. l;

Fig. 8 is a section taken substantially on line 8 8 of Fig. 7;

Fig. 9 is a vertical sectional view through an- 2 other form of refrigerator cabinet embodying the invention; and

Fig. l0 is a horizontal section through the structure shown in Fig. 9; 25

It is to be understood that while I have illustrated my invention as applied to a household refrigerator cabinet, it has utility in other instances where the advantages and results alforded thereby are desired, such, for example, (without limiting the generality), as various kinds of refrigerators, ice boxes, refrigerator cars, cold storage vaults, furnaces, boilers, buildings, bake ovens, dryers, hot rooms, railway cars, automotive vehicles, y spray booths, aircraft, Vessels, etc.

The structure of Figs. 1 to 8, inclusive, includes an outer, rectangularly-shaped shell l0 (Figs. 1,

2 and 3) enclosing a similarly-shaped and spaced inner shell Il providing a continuous space of substantially uniform depth around the several walls of the structure. The inner shell serves as a liner forming a refrigerating and food compartment I2. These shells are preferably formed of comparatively thin sheet metal, but it is to be understood that, if desired, they may be formed of any other suitable kind of material of varying thicknesses without departingfrom my invention.

The top of the outer shell (Fig. l) is formed by a removable, metallic cap member i3 and its bottom is closed by a plate I4, preferably, secured permanently in place in any desired manner. The outer shell l0 extends downwardly in skirt-like fashion beneath the bottom piece I4 where it is connected to a plurality of legs l5 for supporting the structure in upright condition.

The front wall I6 l(Figs. 2 and 3) of the inner shell is provided with a rectangularly-shaped opening defined by a relatively narrow, outwardly and upwardly extending ange I1 and the front wall I8 of the 'outer shell is provided with an aligned and larger opening of similar shapedefront walls I6 and I8 of the shells together and thereby partially hold the same .in spaced relation. The two shells are additionally supported 4in spaced relation by the insulation structure which will be described hereinafter.

The door 22 is provided with an inner wall 23 (Figs. 2 and 3) of rectangular form and a similarly shaped, but larger, outer wall 24. These walls are provided, respectively, with flanges 25and 25 similar to the shell flanges I'I and I9. These flanges are joined together by facing strips 21 extending around the several sides of the door walls 23 and 24 thereby providing a comparatively deep and hollow door that is shaped complementally to the door opening 2|.

The outer door wall 24 is ofsuflicient vsize to overlie the outer shell wall I8 adjacent the entrance to the door opening. The overlying edge. of the outer door wall is turned back upon itself,

as at 28, to properly position its flange 26 within the limits of the door for reception of the facing strips 21. A bumper strip 29 formed of rubber, or other suitable, resilient and cushioning material, is secured to the underside 'of the overlying door'edge 28 on all sides of the door. This mem- Aber 29 is adapted to seat against the outer shell wall I 8 around the door opening when the door 22 l is closed to seal the inner shell compartment I2 from the atmosphere.

The door 22 supports, at one side edge thereof, the requisite number of hinges 30 (Fig. 3) which are secured in any suitable manner to the outer shell wall I8 for swingingly supporting the door for its opening and closing movements. The opposite side edge of the door may be provided with any suitable form of latching means (not shown) adapted to engage shell-carried latch means (not shown) for holding the door closed.

Thermal insulating structure is mounted within the space between the shells I 0 and I I and within the door. The insulating structure shown in the drawings takes the form of a plurality of units so constructed and mounted between the shells I0 and II as to divide the space therebetween and along the several ysides thereof into separate, disconnected, enclosed and uni-planar air spaces; and these units are also so arranged that they support, brace and strengthen the door and shell walls and provide a substantially rigid cabinet or the like structure. Y

The insulation structure shown in Figs. 1 to 8, inclusive, includes a back wall unit 3| (Fig. 4), two similar side wall'units 32 (Fig. 5), a bottom wall unit 33 (Fig. '7), a top wall unit 33' (Fig. 2) similar to the bottom wall unit, and door unit 34 (Fig. 6).

Each of the insulating units is of general rectangular shape and includes a frame comprised of a plurality of sections (one for each side of the frame) each of which is, in turn, made up of a plurality of superimposed slabs of fiber board, or other suitable non-conducting material. The slabs of each frame section are so related to each 5 other lthat the adjacent ends of the several sections interflt each other in a manner to produce bonded frame corners providing a frame structure which is rigid as a whole. Each unit further includes af plurality of metallic sheets supported 1o between the frame section slabs in spaced relation with respect to each other and to the shell an'd`do0r walls so as to divide each of the several spaces to be insulated into a plurality of disconnected 'and substantially sealed air chambers ex- 15 tending throughout the length and width of the plane of each space to be insulated. The several metallic sheets are substantially parallel with respect to each other and they provide uni-planar air chambers which are of substantially uniform 20 depth throughout the plane of each and which f are substantially free from convection currents.

All of the sheets of all of the units are preferably formed of the same material, and are, preferably, of similar shape and only one group of the same 25 need berdescribed in detail. v v

Each metallic sheet is formed, preferably, of a dull, non-bright 'metallic material which reflects alow percentage of yvisible light (such as, for example, without limiting the generality,` com- 30 mercial black steel, galvanized iron or steel, dullsurfaced rustproof metals, copper,'etc.) as dis-V tinguished from bright, silver-like surfaces or materials (such, for example, as aluminum foil, tinfoil, etc.) which reflect a high percentage of 35 visible light. It is to be understood, however, that so far as the bracing, supporting and certain other of the structural features of my invention are concerned, any suitable kind of material adapted to give the desired insulation value under the existent conditions of use may be employed, without departing from my invention.

As more fully explained in my said co-pendlng application, Serial No. 629,089, the wave lengths of visible light are shorter than the wave lengths of radiant heat under temperature conditions existent in practically all insulation elds; and bright, silver-like surfaces are, therefore, due to the fact that their maximum radiant reflectivity lies within the visible portion of the spectrum, .-,0 effective to insulate most eiciently against radiant heat over that range in the electromagnetic spectrum which overlaps into visible light. As is well-known, this range is comparatively slight and the eiciency of such waves as carriers of 5 energy is very low, ranging fromv 2% to 3%. I have found that where radiant heat is emitted at wave lengths longer than those of visible light (which is the case in practically all ordinary thermal insulation fields), dull, non-bright, me-- tallic surfaces (relatively low reflectors of visible light), such for example as those hereinabove mentioned, become high reflectors of radiant heat and their use results in higher insulation eiliciency due to their increased insulation against the transfer of heat by radiation. I, therefore, preferably, employ metallic sheets of a character which normally possess relatively low reflective characteristics when exposed to radiation of wave lengths within the visible portion of the 7g electromagnetic spectrum and relatively high reflective characteristics when exposed to radiation of longer wave lengths longer than the visible portion of the electromagnetic spectrum.

The metallic sheets employed in carrying out my invention, as more fully explained invmy aforesaid co-pending application, are also utilized for the formation of so-called laminar-flow orV theoretical flow 4or non-turbulent gas films which have the abilityv to prevent convection transfer of heat. These films alsol have the normal ability of air as a gas to insulate against the4 transfer of heat* by conduction. Further, these films are practically transparent to radiation, but due to the ability of the metallic sheets to minimize the transfer of radiantl heat, as .above eX- plained, the sumvtotal effect of the metallic sheetsv tersecting plane surfaces, the number of suchsurfaces depending upon the dimensions of the sheet. Additional insulation value (as more fullyl pointed out in my aforesaid copending application) is afforded by thus preforming the surfaces of each sheet.` Preforming also adds rigidity andstiffness to the sheet and prevents propagation of sound waves by vibration of the sheets and consequently the shell walls defining the insulating structure.

More particularly, referring to Figs. 2 to 7, inclusive, it will be seen that`each sheet is divided into angularly disposed plane surfaces 35 and that the adjacent plane surfaces intersect approximately at the points 36. Each sheet is provided at the points of intersection of its planesurfaces with ribs 31, which `are preferably so formed and arranged as to not extend the surfaces of the sheet beyond their normal plane. The adjacent ribs of each sheet are turned in opposite directions in order to meet this condition and the opposed ribs of adjacent sheets are similarly directed so that, in theusegof a plurality of metallic sheets, this relationship .is maintained throughout the entire insulating unit. The ribs 31 extend, preferably, in vertical direction inver,- tically-disposed wall spaces'and horizontally vin horizontally-disposed spaces. In the use ,of a plurality of sheets, corresponding plane surfaces and ribs on adjacent sheets are arranged in substantially parallel relation so that the surfaces of the sheets are substantially equi-distant at al1 points throughout the planes thereof.

For best insulation results, as fully pointed out in my aforesaid co-pending application, the several metallic sheets of each unit (Figs. 4, 5, 6 and 7) are so spaced apart that the central plane of the group of the same is disposed-at a point closer to the higher temperature wall surface '(or outer shell I0) than to the lower vtemperature wall surface (or inner shell II). In

such arrangement of sheets, the metallic sheet `nearest the higher temperature wall surface (or outer shell I0) is spaced comparatively close to such surface with the other sheets, preferably, spaced progressively farther apart from each other as they approach the lower temperature. wall surface (or inner shell I I).

vided forby locating the center of gravity or the ping slabs 5| and 521 While I have found that high insulation efliciency may be procentral plane of the group of sheets on the ther- I mal fulcrum point of the space defined by the inner and outer walls or shells I0, II, excellent resultsare also obtainable by positioning such central plane at different points within the space between the shells Ill and II which fall within the kdimensional limits of less than one-half and walls or shells. It will be understood that, while the units v more than one-third of the distance between the shown vand described herein embody a plurality 4 of metallic sheets, one sheet only (not shown) may be employed in certain casesfas morel particularly pointed out in my said co-pending application'. In the use of a single sheet of metal it should be located similarly to the central plane of a group of sheets as above explained.

Referring nowjmore particularly to the several insulationfunits of the structure of Figs. 1 tofv 8, inclusive, the bottom unit 33 (Fig. 7)` includ'es' (preferably but not necessarily), five metallic sheets 40 to 44, inclusive, which are supported in the space between the bottoms of the sheets (Figs. 1 and. 2) by a rectangular-ly shaped frame 46 (Fig. 1) of such size thatits outer edges seat uniformlyagainst the outer shell IU at the several sides of the latter. The frame 46, cooperatively with the shell Walls, forms an enclosed bottom spacel 45 Ato be insulated.

'Ihe bottom frame 46 includes laminated sections 41, 48, 49 and 50 (one for each: side) each of which is formed of a plurality of superimposed j slabs or pieces 5I to 56, inclusive. The slabs or pieces 5I which are disposed closerv tothe bottom' yI4 of the outer shell (or higher temperature wall) are thinnest while the other slabs 52, 53,

54, and 56 progressively increase in thickness.

The edges of the metallic 'sheets 40 to 44 are` slab overlaps the adjacent end of the adjacent slab or slabs a distance, approximately equal to the width of the slabs. of slab 5I overlaps end b of slab-52, while end c of slab52 overlaps end d of slab 5I a distance approximately equal to the width of the overlap- By similarly overlapping In other words, end a the other adjacent slabs of each section,there are provided at the opposite ends of each section a plurality of spaced, vertically4 staggered (at opposite ends), projecting tongues a and c dening vertically staggered'` spaces which receive similar tongues of the adjacent ends of the adjacent sections (Fig. 7). By thus intertting the adjacent ends of adjacent'frame sections, there,l

is provided a laminated frame, each lamination of .which consists of six slabs having right-angu- V lar butt-joint engagement with each other. Each slab is so positioned with respect .to adjacent slabs'that its one end has endwise right-angled abutting engagement with the side of one o'f the adjacent slabs adjacent one end of the latter and its other end is similarly engaged by one end ofl the. other adjacent slab whereby successive butt-joints in each lamination are disposed at right angles to each other. Furthermore, the staggering of slabs in each frame section serves to stagger the butt-joint of one lamination relative to the butt-joint adjacent lamination whereby the butt-joint of each lamination is supported by a plain and unjointed surface of the adjacent lamination.

The several frame laminations are rigidly secured together by a plurality of similar metallic staples, or other suitable fastening devices, indicated at 51, 58 and 59, and when they are so secured they provide, due to the above-described arrangement of slabs and laminations, a unitary and very' rigid frame structure which is not subject to weaving and warping under normal con-l ditions of use. The metallic sheets extend far enough between the frameslabs for the innermost staples 59 to pass therethrough and thereby electrically ground the metallic sheets to each other. In this manner, the metallic sheets are brought to the same electrical polarity, electrolysis and electro-chemical deterioration are prevented, and additional thermal insulation value is added to the unit.

The rear and side bottom portions of the inner l shell are adapted to seat upon the bottom insulating unit for support of the former (Figs. 1 and 2). To this end, the uppermost slab 56 of the bottom-unit is of greater width than the slabs therebeneath (Fig. '1) so that its inner edge projects beneath the inner shell. Due to the extreme rigidity of the frame 46, the uppermost (and thicker) slabs 56 well serve as a support for the inner shell, permitting the lower slabs to be of less widthso as to expose a greater area of the metallic sheets within the bottom space.

The top insulating unit 33 is of substantially the same construction as the bottom unit 33 (Fig. 1. Its lowermost frame slabs 10 (Figs. 1 and 2) correspond to the uppermost slabs 56 of the bottom unit and they seat upon the top of the inner shell at the rear and sides of the latter. In this manner additional support is given to the linner shell, preventing displacement of the same vertically or angularly. The slabs 1D of the top unit also abut the upper sides of the side and rear insulating sections; and the frame of unit 33', together with the shell walls, forms an enclosed top space 10"L to be insulated.

In shaping the door opening 2| as hereinabove described, wedge-shaped wall spaces 1| and 12 (Fig. 2) are formed along the top and bottom of the door opening. These spaces are lled with similarly-shaped blocks 13 and 14, respectively, formed of fiber board, or the like material, the flat base surfaces of such blocks being flush with the exterior bottom and top walls of the inner shell The slab sections 56 and 10 of the bottom and top units seat against these blocks for support of the front portion of the inner shell. The blocks 13 and 14 may be mounted separately from theinsulation units, or, if desired, they may-be secured thereto bythe rivets 51, 58 and 59(01 other suitable fastening means) so as to constitute a fixed part of the insulation unit.

The rear Iwall insulating unit 3| (Fig. 4) is of the same general construction as the top and bottom units 33 and 33' previously described, except that it includes, preferably, four (instead of ve) metallic sheets. This unit includes a frame 80 formed of a plurality of sections 8|, 82, 83 and 84 (one for each side) and it is of such shape and width as a whole that its side sections 82 and 84 seat against the opposite side Walls of the outer shell adjacent the rear corners of the latter. These side frame sections are also of a width substantially equal to the width of the space between the shells whereby they 5 fill and completely block off the rear vertical corner parts of the space between the shells. The frame 80 serves with the shell walls to form the enclosed rear insulation space 6| which is substantially of the length and width dimensions of 10 the rear wall of the inner shell.

The top and bottom portions of the rear corner parts of the space between the shells is filled and blocked oi by the frames of the top and bottom units against which the top and bottom sections 15 8| and 83 of the rear unit 3| abut. These top and bottom unit frame sections 8| and 83 are of minimum width so that the rear space 6| extends substantially throughout the length and width of the rear Wall of the inner shell.

The rear, top and bottom units engage each other in a right-angle butt-joint fashion whereby rigidity is added to the structure as a whole bythe arrangement of the rigid units. The side units 32, which will now be referred to in greater detail, also abut the other units in a like manner to the end just stated.

The side units 32, which are identical, are of the same general construction as the previously described units. Each side unit includes a plurality (preferably, but not necessarily, four) of metallic sheets 9|), 9|, 92 and 93. These sheets are supported by a rigid frame 94 which is comprised of a plurality of sections 95, 96, 91 and 98 (one at each side) made up of a, plurality of slabs arranged and bonded together at the corners of the frame similarly to the slabs of the top, bottom and rear units. The frame 94 is of such size and shape that its top section 95 seats against the lower slab 10 of the top 40 unit 33', its bottom section 91 seats against the upper slab 56 of the bottom unit 33, and its rear side section 96 seats against the innermost slab (82 or 84 as the case may be) of the rear unit 3|. The front section S8 is of a width substantially equal to the depth of the space between the front Walls of the inner and outer shells and it isof a thickness somewhat greater than the depth of the side spaces between the shells so that it occupies and blocks off the front vertical corner parts of the space between the inner and outer shells for a distance falling substantially within the height of the inner shell. In this manner, the frames 94 together with the shell Walls form enclosed side wall spaces 60 of substantially the outline dimensions of the sides of the inner shell Unit insulation panels constructed as above described form a rigid, strong and durable structure in themselves. The formed steel sheets provide reinforcing webs able to withstand the shearing and diagonal tension stresses imposed upon the same; and the frame edge structure forms a ange able to withstand the tensile and compressive stresses imposed upon it. When asincludes a plurality (preferably, but not necessarily, live) metallic sheets llll to H4, inclusive, supported by a sectional and rigid frame lili. The frame liti has its outer surface shaped similarly to the door 22 so as to iit within the wedgeshaped door space formed by the door walls 23 and 24. It will be noted that the frame H5 approximates the dimensions of this door space so that the unit fits snugly therein to brace the door Walls and provide a rigid door structure. This frame Ialso denes an. insuation space tit of regular rectangular outline shape which extends substantially throughout the surface of the inner door wall 23 that is disposed next to the inner shell.

It will be obvious from the foregoing description that the several insulating units are so constructed and mounted with respect to each other and the shell walls that they provide a plurality of uni-planar, separate and disconnected insulating spaces between and along the several walls of the inner and outer shells. 'I'hese spaces are divided by the substantially parallel metallic sheets into a pluralityy of unobstructed, substantialiy sealed and uni-planer disconnected air chambers of substantially uniform depth that are substantially free from convection currents.v

The unit frame members, and particularly the corner-blocking portions thereof block oi and minimize heat leakage `at the several corners of the shells and prevent any material drop in percentage of efficiency from that cause.

In Figs. 9 and 10, I have illustrated another form of my invention as applied to an all-metal refrigerator cabinet, including an outer shell |20 and an inner shell |2| supported therein in spaced relation` by suitable leg members |22. This shell arrangement, inclusive of the door |23, is similar to the shell structure of the previously-described form, except for the supporting legs |22 and plate members |24 blocking oi the wedge-shaped spaces |25 formed incidentally by the wedge-shaping of the door opening |26. In this manner, a substantially continuous space |21 is formed in the side, rear, bottom and top walls of the cabinet structure.

Like in the previously described form of my invention, a plurality of insulating units (bottom), |3| (top), |32 (side), |33 (rear) and |34 (door) are mounted in the space |21 along the respective walls of the cabinet structure so as to divide such space into a plurality of disconnected spaces to be insulated (one along each wall). The insulating units are each so constructed as to divide each of theseI wall spaces into a plurality of unobstructed, disconnected, uni-planar and substantially sealed air chambers free from convection currents similarly to the insulating units of the previously described form.

The several insulating units are identical in construction, except as for size variation and only one of these units need be described in detail. The unit includes two metallic sheets sheet |40 which is, preferably, adapted to be disposed adjacent the outer Wall |20. The several edges of this sheet are similarly formed to provide, in effect, a supporting edge-seal head lill of V-shaped cross section and of a Width dimension somewhat greater than the depth of the space |21. i

The insulating unit includes another sheet |62 which is supported in nested relation by the edge-seal head |4| of the sheet' |40 in spaced relation to the latter. with a completely circumscribing laterally-extending edge flange |43 which is beaded as at I4@ for interlocking engagement with a bead |45 formed in the supporting sheet head IM. The'dimensions of the sheet |42 are, preferably, such with respect to the supporting head |4| that its flange |43 must be sprung slightly but snugly into detachable interlocking engagement with its supporting head so that this sheet is firmly and securely supported in predetermined spaced condition with respect to the sheet |40 Without the use of separate fastening means. To further eifect this securement, the sheet head |4| has its free edge |46 slightly extended and turned back upon and over the free edge of the sheet edge flange |43. By thus associating the sheets, they are electrically grounded to each other (and to the shell walls as will become obvious hereinafter) for additional insulating ef-v fect as hereinbefore pointed out. These metallic sheets |40 and |42 are, preferably, mounted in planes parallel with the plane of each other and with the planes of the shell walls. By arranging the sheets in this manner and by sealing the edges of the same, they provide, cooperatively with each other, the shell walls and the adjacent units, spaces that are edge-sealed vand of substantially uniform depth throughout.

Support of the several units ls provided for as follows: The edge-seal members of the adjacent units at the corners of the space |21 are so related that they abut and nd support upon each other in the manner clearly illustrated in Figs. 9 and l0. Thusly, the several units in the space |21 are electrically grounded to each other and to the shell walls and they are so related that the several spaces between the units and the shell walls are completely closed and blocked off along the several walls of the structure.

The shape of the edge seal heads |4| is such as to ail'ord flexibility of the same in a lateral direction as well as in the plane of the sheets.

This sheet |42 is provided f The width of the head is slightly greater than abutting surfaces so that each unit as a whole 75 is grippingly and yieldingly retained in a predetermined position Within its intended space. In this manner, the units may be applied without the use of separate fastening means. This form of mounting compensates for thermal expansion and contraction of the sheets and it also insures that the sheets will be held firmly in place without rattling or other objectionable conditions which would exist should the same be or become loose. Still further, this arrangement aords readiness and ease in the installation of the units, as well as facilitating manufacture of the same to the end of exceedingly low cost.

Other than above described, the construction and operation of this form of my invention is the same as that previously described.

In the use of the structures herein described, the metallic sheets, while being themselves conductors of heat, establish conditions reducing the iow of heat through the walls to a point which, so far as I know, has never heretofore been attained. By employing insulating units, sized, shaped and mounted in the manner described, the insulation units themselves serve to support the shells with respect to each other and'transform the entire cabinet structure into a highly durable and rigid unit, greatly eliminating noise and vibration from the moving parts of the refrigerating machine. The shells may be formed of a relatively thin and lcheaper material than heretofore possible without sacricing strength and durability of the cabinet as a whole. The

entire cabinet structure, including the insulation, is composed of a few parts which may be readily and quickly assembled and disassembled. Maintenance attention is reduced to the minimum. All of these features tend to materially decrease the cost of structurenof this character. Low cost is attained with increased insulation value and with an insulation value which is substantially constant for practically'the entire life of the cabinet.

Metallic sheets used in accordance with my invention may be formed of material quite inexpensive as compared to materials heretofore employed. Materials ordinarily subject to rusting, corrosion, etc., when subjected to moisture conditions, may readily be employed without lessenin'g the life of the insulating structure from such cause. This is due particularly in view of the fact that my invention established conditions within the space to be insulated of a character whereby moisture is not condensed from the air upon the insulation or the walls, and the space and structure therein remain free from condensate and the well-known detrimental efiects thereof. It will be understood, however, that, if desired, metallic sheets may be formed of a rustproof material having the reflective characterlstics required for carrying out my invention, or non-rustproof metallic sheets may be subject to any known rustprooflng process which does not impair the normal heat reecting characteristics of the material. For example, the metallic sheets, either before or after performing the same, may be treated so as to provide the same with a coat of ferrous phosphate, or the like, which renders the sheet rustproof but does not change its radiant heat reecting ability in the region of the longer wave lengths of radiant energy. v

It will be understood that, while I have shown and described only two adaptations of my invention, various changes in details and arrangements of parts may be made without departing from the spirit and scope of my invention as dened by the claims which follow.

I claim:

l. In structure of the class described, a. plurality of walls extending at an angle with respect to each other and formed by spaced wall surfaces defining a substantially continuous space along said walls, a plurality of seal members, one for each of said walls, mounted in said space and Abounding the edges of the latter, each said seal member being continuous and forming with the adjacent Wall surfaces a completely enclosed space to be insulated, a plurality of heat-insulating metallic sheets supported by each of said seal members in substantially parallel and spaced relation with respect to each other and to said wall surfaces, said seal members being so arranged in said continuous space that the seal member along one Wall abuts the seal memb ers along adjacent walls to position said seal members with respect to each other and said wall surfaces.

2. In structure of the class described, a plurality of walls formed by spaced wall members dening a substantially continuous space along said walls, a plurality of continuous, closed gure seal members, one for each of said walls, mounted in said space in abutting relation with respect to each other and said wall members so that each said seal member forms with the surfaces of the adjacent wall members independent and enclosed uni-planar spaces to be insulated, and a plurality of commercial black steel sheet members of the outline shape of said insulating spaces and having their `edge portions only supported by said seal members inspaced and substantially parallel relation with respect to each other and to said wall members and dividing said insulating space into a plurality of uni-planar and substantially sealed and parallel air chambers.

3. In structure of the class described, a plurality of walls formed by spaced wall members dening a, substantially continuous space along said walls, a plurality of continuous, closed-figure seal members mounted in said space and bounding the edges of the latter, each said seal member forming with the adjacent wall members of the space bounded, an enclosed space to be insulated, a plurality of metallic sheets having their edges supported by each of said seal members in spaced relation to each other and to said Wall members, said sheets being formed of a material which possesses relatively low -reective characteristics when exposed to radiation of wave lengths within thevisible portion of the electromagnetic spectrum and relatively high reflective characteristics when exposed to radiation of longer wave lengths than the visible portion of the electromagnetic spectrum, and said seal members being so arranged in said continuous space that they abut each other to position said seal members with respect to each other and said wall members.

4. In structure of the class described, spaced inner and outer rectangularly-shaped shell members defining a walled structure having a space extending around the walls thereof in a substantially continuous fashion, a substantially rigid frame member mounted in the space along each wall and. dening with the adjacent shell surfaces a space to be insulated of approximately the outline dimensions of the respective inner shell wall, said frames along adjacent walls being so constructed and arranged that they abut and find support upon each other, a plurality of relatively stiff sheet members carried by each of said sheet members dividing said space to be insulated into a plurality of substantially sealed air chambers substantially parallel vWith-the planes of said space to be insulated and substantially free from convection currents, and said sheets being formed of a material which possesses relatively low reilective characteristics when exposed, to radiation of wave lengths within the Visible portion of the electromagnetic spectrum' and relatively high reilective characteristics when exposed to radia- `tion of wave lengths longer than the visible portion of the electromagnetic spectrum.

5. In structure of the class described, a plurality of Walls each formed by spacedwall membersv denng a space, and means for thermally insulating said walls which comprises a frame member for each wall extending around the edges of the Y. space bounding each wall and providing with;

the bounded wall surfaces an enclosed spaceto be insulated, said 4frames being so constructed and arranged that each frame finds support upon the'adjacent frames and Wall surfaces. and a plurality of metallic sheets carried by each said frame in spaced relation to each other and to the wall surfaces deiining the respective enclosed space and dividing said enclosed space into a plurality of substantially sealed air chambers, said sheets being so supported by said frames' that the sheet next adjacent to one wall is comparatively close thereto and the other sheets are spaced progressively greater distances apart, and said sheets also being formed of a material possessing relatively loW *reilective-characteristics when exposed to radiation of wave lengths with--A in the visible portion of the electromagnetic spectrum and relatively high reflective characteristics when exposed to radiation of Wave lengths longer than the visible portion of the electromagnetic spectrum.l l

6. In structure of the class described, a plurality of hollow walls disposed at substantially right angles with respect to each other and defining a plurality of normally interconnected wall spaces disposed at substantially right angles to' each other, a rectangular frame member extending continuously around the edges of the space each other and so that they are spaced from the adjacent space-defining wall surfaces, said sheets being of suiiicient thickness and stiiness to withstand preformed shape and dividing said enclosed space into a plurality of substantially sealed air chambers substantially free from convection currents.

'7. In Istructure of the class described, spaced inner and outer, rectangularly-shaped shells providing top, bottom, side and rear wall spaces, and means for thermally insulating said'spaces which includes a bottom unit having a continuous frame member forming with the bottom walls of said shells a bottom enclosedspace, and a plurality of spaced heat-insulating metallic sheets having their edges carried by said frame members, side and rear units similar to said bottom unit mounted in said side and rear spaces and supported upon-said bottom unit, and a top unit similar to said bottom unit mountedin said top space and seated upon the upper edges of said side and rear units, the side edges of said side vunits vhaving butt-joint `engagement with said rear unit. 5

8. Instructure of the class described, spaced innerand outer, rectangularly-shaped shells providing top, bottom, sideand rear Wall spaces, and means thermally insulating said spaces which includes a bottom unit of a character forming 10 with thebottom walls of said shells a bottom enclosed space, similar side and rear units mounted insaidside and rear.- spaces and supy ported upor said bottom unit, and a similar top unit mount-ed in said top space and seated upon the upper edges of said side and rear units, said side units having butt-joint engagementv with said rear unit, and a pluralityof metallic sheets forming a part of each of said units and dividing the respective insulating spaces-formed by the '20 units into a plurality, of substantially sealedr chambers substantiallyfree from convection curl rents, said sheets being formed of a material pos-f sessing relatively low reflective, characteristics when exposed to radiation of Wave lengths Within the visible portion of the electromagnetic spectrum and relatively high reflective characteristics when exposed to radiation of Wave lengths longer than the avisible portion of, the electromagnetic spectrum.

' 9 In nstructure of the class described, spaced inner and outer shells providingtop, bottom, side and rear wall spaces, and means for thermally insulating said spaces which comprises similar spaces, each of which units includes/a continuous frame and a plurality of steel sheets having their edge portions only supported by the frame in spaced relation to each other and to the walls dening the respective space, said frames be- 40 ing so constructed and arranged that they each provide with the adjacent shellwalls an enclosed. space of such dimensions that it extends substantially throughout the surface of the vrespective inner shell wall, and said frame which is adapted to be inserted in the bottom space being of such cross-sectional size that it extends slightly beneath the bottom of said inner shell to support the latter, and the other of said frames having abutting engagement with each other and -l both4 said shells to positively position all such parts with respect to each and to provide strong and durable Walls. Y,

10.4 A thermal insulating unit which comprises a continuous frame in the form of a closed gure land formed of a plurality of laminated sections,

each of said sections having its opposite` ends formed for corner-bond, butt-joint interlock engagement with the adjacent sections providing a substantially rigid structure, and a pluralityl of vcommercial steel sheets having their edges only mounted between the laminations of said frame l to mount said sheets in spaced and substantially parallel relation with respect to each other with the greater portion of their surfaces unobstructa frame having a plurality of laminated sections formed o f a material possessing relatively 10W heat conducting characteristics/each of said sections/having its opposite ends formed for securement to the adjacent sections providing a sub- 75,

stantially rigid Structure, and a plurality of metallic sheets having their edges mounted between the laminations of said frame to mount said sheets in spaced relation to each other with the greater portion of their surfaces unobstructed, said sheets being formed of a material possessing relatively low reective characteristics when eX- posed to radiation of wave lengths within the visible portion of the electromagnetic spectrum and relatively high reflective characteristics when exposed to radiation of wave lengths longer than the visible portion of the electromagnetic spectrum, and means for securing said laminations, sections and sheets together as a rigid unit.

12. A thermal insulating unit which comprises a continuous frame in the form of a closed figure and formed of a plurality of laminated sections, each of said sections having its opposite ends formed for corner-bond, butt-joint interlock engagement with the adjacent sections providing a substantially rigid structure, and a plurality of steel sheets of suflicient thickness and stiffness to withstand preformed shape having their edges only mounted between the laminations of said frame to mount said sheets in spaced relation to cach other with the greater portion of their surfaces unobstructed, certain of the laminations of said sections being of variable thickness to space said metallic sheets variable distances apart, andv means passing through said laminations and sheets for securing said sections and sheets together to provide a comparatively rigid unit, and to electrically ground said sheets.

13. A thermal insulating unit which comprises at least one metallic sheet, a frame bounding the edges of said sheet leaving the remainder of the sheet surface unobstructed, said frame being formed of a plurality of laminated sections having their opposite ends formed for' bonded engagement with the adjacent sections to provide a substantially rigid frame, said sheet being formed of a material possessing relatively low reflective characteristics when exposed to radiation of wave lengths within the visible portion of the electromagnetic spectrum and relatively high reflective characteristics when exposed to radiation of Wave lengths longer than the visible portion of the electromagnetic spectrum, which sheet has its edges mounted between said laminations, and means for securing together said laminations, sections and sheet.

14. A plural-walled structure which comprises a plurality of spaced wall members defining a substantially continuous space extending along the several walls of the structure, and means for insulating said space which includes an insulating unit for eacnwall including means associated therewith to form with said Wall members along each wall an enclosed and substantially sealed space entirely separated from the other spaces, said unit including a plurality of sheet surfaces arranged in spaced and substantially parallel relation in said sealed space and dividing said sealed of metallic surfaces arranged in spaced and sub Y stantially parallel relation in said sealed space and dividing said sealed spaces into a plurality of substantially sealed chambers, said surfaces being of a kind possessing relatively low reflective characteristics when exposed to radiation of wave lengths within the visible portion of the electromagnetic spectrum and relative high reflective characteristics when exposed to radiation of wave lengths longer than the visible portion of the electromagnetic` spectrum.

16. A plural-'walled structure which comprises a plurality of spaced wall members defining a main space along the several walls of the structure, and means for insulating said main space which comprises a unit for each of the walls of the structure, each which unit includes a plurality of heat-insulating metallic sheets, an edgeseal means carried by one of said sheets and supporting said sheets in spaced relation with respect to each other, said edge seal means forming with the wall surfaces bounded thereby an enclosed insulating space with said metallic sheets dividing said insulating space into a plurality of substantially sealed air chambers, and said units being so sized and arranged in said main space that the edge-seal means of the adjacent said units abut each other for support of said units.

17. A plural-walled structure which comprises a plurality of spaced `wall members dening a main space along the several walls of the structure, and means for insulating said main space which comprises .a unit for each of the walls of the structure, each which unit includes a plurality of heat-insulating metallic sheets, a metallic, and yieldable edge-seal head carried by one of said sheets and supporting said sheets in spaced relation with respect to each other, said edge seal head being engaged with the respective spaced wall members and forming with the Wall surfaces bounded thereby an enclosed insulating space with said metallic sheets dividing said insulating space into a plurality of substantially sealed air` chambers, and said units being so sized and arranged in said main space that the edge-seal heads of the adjacent said units abut each other for Asupport of said units upon each other.

JOSEPH M. LE GRAND. 

